1. Field of the Invention
The present invention relates to a numerical control device for a compound machine tool that enables lathe turning and milling to be performed on the same machine.
2. Description of the Related Art
Conventional numerical control devices for compound machine tools have no interactive facility for supporting an arrangement operation in producing a working program or measuring a tool compensation amount. A compound machine tool has a lathe turning mode and a milling mode to perform both the lathe turning and the milling. Each mode has a different program format, and an NC program corresponding to each working mode must be created. Also, an NC program for switching between these working modes must be created.
Further, to effect work in each working mode, it is required for each working program to set up the tool compensation amounts for lathe turning and milling, separately, which operation is very complex
FIG. 6 is a schematic diagram of a conventional numerical control device for a compound machine tool.
The numerical control device for a compound machine tool is composed of a CPU, a memory, a display unit, an input device such as a keyboard, and an input/output interface. A software storage area is divided into a lathe turning software storage area 1 and a milling software storage area 2, in which lathe turning control software 4 is stored in the lathe turning software storage area 1, and milling control software 5 is stored in the milling software storage area 2.
In the hardware configuration, there are both cases where separate CPUs are provided for the lathe turning and the milling and where a single CPU is shared. In the latter case, the CPU is shared between two software programs by time division.
A compound machine tool working program 3 is stored in either the lathe turning software storage area 1 or the milling software storage area 2. In an example of FIG. 6, it is stored in the lathe turning software storage area 1. This compound machine tool working program 3 consists of a lathe turning program and a milling program in a single working program, which are discriminated in accordance with an M code Myy for instructing a lathe turning and an M code Mxx for instructing a milling, as shown in FIG. 6.
This compound machine tool working program 3 is executed, and if the M code Myy for instructing a lathe turning is read, the lathe turning control software 4 is initiated to read the lathe turning program that is programmed after the M code Myy, making the analysis and interpolation, and performing the lathe turning. Also, if the M code Mxx for instructing the milling is read, the milling control software 5 is initiated to read the milling program that is programmed after the M code Mxx, making the analysis and interpolation, and performing the milling.
Reference numeral 6 denotes a switch facility for selecting an axis movement command (servo command) to be outputted to a servo amplifier 7 if the M code Myy or M code Mxx is read from the compound machine tool working program 3. If the lathe turning M code Myy is read, the switch 6 outputs an axis movement command processed and outputted by the lathe turning control software 4 to the servo amplifier 7 for each axis. Also, if the milling M code Mxx is read, the switch is changed from-a state of FIG. 6 to an inverse state, and outputs an axis movement command processed and outputted by the milling control software 5 to the servo amplifier 7 for each axis.
The servo amplifier 7 for each axis drives a servo motor 8 based on the axis movement command, and moves each shaft connected thereto to perform the lathe turning or milling.
Reference numeral 9 denotes a switch or other switching means on an operator control panel 11 to selectively start either the lathe turning control software 4 or the milling control software 5. A display unit 10 displays a working program and various sorts of data required for the working operation. The operator control panel 11 having a keyboard and the like is employed to input a working program and various sorts of data required for the working operation.
FIG. 7 is a flowchart of an input setting operation for inputting a working program or various sorts of set values such as tool compensation amount in the numerical control device for a compound machine tool.
First of all, the display unit 10 is switched to a working program inputting screen, as shown in FIG. 8. For the input of a lathe turning program, a lathe turning M code Myy is inputted, and a lathe turning program is inputted, employing the keyboard on the operator control panel 11 (operations 201 to 203). Also, for the input of a milling program, a milling M code Mxx is inputted, and a milling program is inputted (operations 201, 204, 205).
If the input of a working program is ended (operation 206), the display unit 10 is switched to a lathe turning data screen, as shown in FIG. 9. In this case, the switch 9 is turned to the side of the lathe turning control software 4, which is thereby initiated to display a lathe turning data input screen on the display unit 10. Based on the lathe turning data input screen that is displayed, various sorts of data such as a tool compensation amount are inputted from the operator control panel 11 and set up (operations 207, 208).
Then, a milling data screen is selected to input and set up milling data. If the milling data screen is selected, the switch 9 is turned to the side of the milling control software 5, which is thereby initiated to display the milling data input screen on the display unit 10, as shown in FIG. 10. Based on the milling data input screen, various sorts of data required for the milling are inputted and set up (operations 209, 210).
In this manner, the composite working program 3 composed of a lathe turning program and a milling program is inputted, and the lathe turning data and the milling data are inputted and set up. Then, a working command is inputted (operation 211). If the lathe turning M code Myy is read based on the input composite working program 3, the lathe turning control software 4 is initiated to read the lathe turning program following the code Myy, making the analysis and interpolation to output an axis movement command to the servo amplifier 7 for each axis, and drive the servo motor 8 for each axis to enable the machine to perform the lathe turning. Also, if the milling M code Mxx is read, the milling control software 5 is initiated to read the milling program, making the analysis and interpolation to output an axis movement command to the servo amplifier 7 for each axis, and drive the servo motor 8 for each axis to enable the machine to perform the milling.
The conventional numerical control device for compound machine tool is operated in the above way. In this conventional numerical control device for a compound machine tool, when a working program is inputted, the working program must be written step-by-step using an NC program language. In order to input various sorts of data such as set values including a tool compensation amount required for the working, in the case of a lathe turning, the lathe turning control software 4 is initiated to display the lathe turning data input screen on the display unit, while, in the case of the milling, the milling control software 5 is initiated to display the milling data input screen on the display unit.
In the above example, the numerical control device for a compound machine tool is employed to make the lathe turning and the milling. However, a numerical control device for a lathe may be employed to make the lathe turning and a simple milling, instead of a numerical control device for compound machine tool.
FIG. 11 is a schematic diagram of a simple type numerical control device for a compound machine tool using a numerical control device for a lathe. The same or like parts are designated by the same reference numerals throughout FIGS. 6 and 11. In a software storage area 21, a working control software 23 and an interactive facility controlling software 24 are stored, and a compound machine tool working program 22 may be stored. As this simple type numerical control device is composed of a numerical control device for a lathe to which a simple milling function is added, the format of the working program for a milling is that of the working program for a lathe turning. Namely, a preparation function (G code) for use in the working program is different between the lathe system and the milling system. Usually, the working program for the lathe turning is produced employing the G code for the lathe system, while the working program for the milling is produced employing the G code for the milling system. However, in this simple type numerical control device for a compound machine tool, which comprises a numerical control device for a lathe, the working program for milling must be created using G codes for lathe system and the like.
Also, the working control software 23, composed of a lathe turning control software as a basis to which a simple milling control software is added, reads a lathe turning program and a milling program in the working program 22 to make analysis and interpolation thereof, and outputs an axis movement command (servo command) to the servo amplifier 7 for each axis. The servo amplifier 7 for each axis drives the servo motor 8 for each axis to move the shaft connected thereto, based on the axis movement command, thereby performing the working operation of the machine.
The interactive facility controlling software 24 allows the working program to be input in a menu format to support an input operation. A menu is displayed on the display unit 10 so that various sorts of data can be inputted on the operator control panel 11 and the like in accordance with the displayed menu. Based on the inputted data, the interactive facility controlling software 23 produces a compound machine tool working program 22.
In order to input and set up various sorts of data required for working, a set-up screen for lathe turning and milling is displayed on the display unit 11. FIG. 12 is an example of a milling data input screen for setting a work coordinate system data. FIG. 13 is an example of a lathe turning data input screen. In this manner, in this simple type numerical control device for a compound machine tool, it is required to input the data by switching the display unit between the lathe turning screen and the milling screen, when inputting various sorts of setting data.
In FIG. 11, reference numeral 25 denotes a flow of data for producing a working program to be stored in the memory area 21. Reference numeral 26 denotes a flow of data when displaying the data such as the tool compensation amount required for the working operation that is stored in the memory on the screen and setting up the input data.
In this simple type numerical control device for a compound machine tool, there are problems in that all the functions necessary for milling are not included, and a working program for milling in the milling format can not be used directly.
As described above, in a conventional numerical control device for a compound machine tool that enables both lathe turning and milling, switching to a lathe turning screen or a milling screen is required when inputting and setting up tool compensation amounts necessary for the operation of either the lathe turning program or the milling program and other data necessary for working operations, resulting in a problem that the operability is not as desired.